National Toxicology Program

National Toxicology Program
https://ntp.niehs.nih.gov/go/17721

TDMS Study 05135-04 Pathology Tables

NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15




       Facility:  Battelle Northwest

       Chemical CAS #:  78-79-5

       Lock Date:  None

       Cage Range:  All

       Reasons For Removal:    All

       Removal Date Range:     All

       Treatment Groups:       Include All






































                                                              Page   1


NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    CONTROL                                | 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
 _____________________________________________________________________________________________________________________|____________|
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                             Page   2                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    CONTROL                                | 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 ENDOCRINE SYSTEM - cont                   |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Parathyroid Gland                       | M  +  +  +  +  +  +  +  +  +                                             |   9        |
                                           |__________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  M  +  +  +  +  +                                             |   9        |
                                           |__________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Clitoral Gland                          | +  +  +  +  M  +  +  +  M  +                                             |   8        |
                                           |__________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
      Abscess                              |          X                                                               |      1     |
                                           |__________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Vagina                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Lymph Node                              |          +                                                               |   1        |
      Renal, Hyperplasia                   |          3                                                               |      1  3.0|
                                           |__________________________________________________________________________|____________|
 _____________________________________________________________________________________________________________________|____________|
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                             Page   3                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    CONTROL                                | 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
   Lymph Node, Bronchial                   | +  +  +  +  +  +  M  +  M  +                                             |   8        |
                                           |__________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | +  +  +  +  +  M  +  +  +  +                                             |   9        |
                                           |__________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | M  M  M  M  M  M  +  M  +  M                                             |   2        |
                                           |__________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Skeletal Muscle                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Peripheral Nerve                        | +  +  +  M  +  +  +  M  +  +                                             |   8        |
                                           |__________________________________________________________________________|____________|
   Spinal Cord                             | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |__________________________________________________________________________|____________|
 _____________________________________________________________________________________________________________________|____________|
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                             Page   4                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    CONTROL                                | 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
   Larynx                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 __________________________________________________________________________________________________________________________________ 
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   5                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    70 PPM                                 | 3| 3| 3| 3| 3| 3| 3| 3| 3| 4|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Liver                                   |       +                                                                  |   1        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Heart                                   |       +                                                                  |   1        |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Spleen                                  |       +                                                                  |   1        |
                                           |__________________________________________________________________________|____________|
   Thymus                                  |       +                                                                  |   1        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Brain                                   |       +                                                                  |   1        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |__________________________________________________________________________|____________|
 _____________________________________________________________________________________________________________________|____________|
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                             Page   6                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    70 PPM                                 | 3| 3| 3| 3| 3| 3| 3| 3| 3| 4|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
   Lung                                    |       +                                                                  |   1        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Kidney                                  |       +                                                                  |   1        |
 __________________________________________________________________________________________________________________________________ 
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   7                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    220 PPM                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Liver                                   |                +                                                         |   1        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Heart                                   |                +                                                         |   1        |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Ovary                                   |                +                                                         |   1        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Spleen                                  |                +                                                         |   1        |
                                           |__________________________________________________________________________|____________|
   Thymus                                  |                +                                                         |   1        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Brain                                   |                +                                                         |   1        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
 _____________________________________________________________________________________________________________________|____________|
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                             Page   8                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    220 PPM                                | 5| 5| 5| 5| 5| 5| 5| 5| 5| 6|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Lung                                    |                +                                                         |   1        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Kidney                                  |                +                                                         |   1        |
 __________________________________________________________________________________________________________________________________ 
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   9                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    700 PPM                                | 7| 7| 7| 7| 7| 7| 7| 7| 7| 8|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
      Epithelium, Hyperplasia              | 4  4  2  3  3  2  4  4  4  4                                             |     10  3.4|
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
      Pigmentation, Melanin                |       2                                                                  |      1  2.0|
                                           |__________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
 _____________________________________________________________________________________________________________________|____________|
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                             Page  10                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    700 PPM                                | 7| 7| 7| 7| 7| 7| 7| 7| 7| 8|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 NERVOUS SYSTEM - cont                     |                                                                          |            |
   Brain                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 __________________________________________________________________________________________________________________________________ 
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  11                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|                                            |      A     |
    2200 PPM                               | 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
      Epithelium, Hyperplasia              | 4  4  2  2  2  4  4     4  2                                             |      9  3.1|
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
      Pigmentation, Melanin                |    1                                                                     |      1  1.0|
                                           |__________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
 _____________________________________________________________________________________________________________________|____________|
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                             Page  12                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|                                            |      A     |
    2200 PPM                               | 9| 9| 9| 9| 9| 9| 9| 9| 9| 0|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 NERVOUS SYSTEM - cont                     |                                                                          |            |
   Brain                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 __________________________________________________________________________________________________________________________________ 
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  13                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                                            |      A     |
    7000 PPM                               | 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
      Vacuolization Cytoplasmic            |    2                                                                     |      1  2.0|
                                           |__________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
      Epithelium, Hyperplasia              | 4  4  4  4  4  2  2  4  2  2                                             |     10  3.2|
                                           |__________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|____________|
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                             Page  14                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                                            |      A     |
    7000 PPM                               | 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  M  +  +  +  +  +  M  +                                             |   8        |
                                           |__________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Clitoral Gland                          | M  +  +  +  +  +  +  M  +  +                                             |   8        |
                                           |__________________________________________________________________________|____________|
   Ovary                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Uterus                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Vagina                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  +  +  +  M  +  +  M  +                                             |   8        |
                                           |__________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | M  +  +  +  +  +  M  +  +  M                                             |   7        |
                                           |__________________________________________________________________________|____________|
 _____________________________________________________________________________________________________________________|____________|
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                             Page  15                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                                            |      A     |
    7000 PPM                               | 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | M  M  M  M  +  M  +  M  M  M                                             |   2        |
                                           |__________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Mammary Gland                           | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Skeletal Muscle                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Peripheral Nerve                        | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Spinal Cord                             | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
 _____________________________________________________________________________________________________________________|____________|
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                             Page  16                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 4| 4| 4| 4| 4| 4| 4| 4| 4| 4|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE FEMALE                      | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                                            |      A     |
    7000 PPM                               | 1| 1| 1| 1| 1| 1| 1| 1| 1| 2|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
   Nose                                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
      Turbinate, Inflammation, Suppurative |             1                                                            |      1  1.0|
                                           |__________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 __________________________________________________________________________________________________________________________________ 
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  17                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    CONTROL                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Esophagus                               | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
      Necrosis                             | 1                                                                        |      1  1.0|
                                           |__________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  M  +  +  +  +                                             |   9        |
                                           |__________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 _____________________________________________________________________________________________________________________|____________|
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                             Page  18                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    CONTROL                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  M  +  +  +                                             |   9        |
                                           |__________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Prostate                                | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
 _____________________________________________________________________________________________________________________|____________|
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                             Page  19                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    CONTROL                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
   Lymph Node, Mandibular                  | M  +  M  M  M  +  +  M  +  +                                             |   5        |
                                           |__________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | +  M  M  M  M  +  M  M  +  +                                             |   4        |
                                           |__________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M                                             |            |
                                           |__________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Skeletal Muscle                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Peripheral Nerve                        | +  +  +  +  M  +  +  +  +  +                                             |   9        |
                                           |__________________________________________________________________________|____________|
   Spinal Cord                             | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Larynx                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
 _____________________________________________________________________________________________________________________|____________|
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                             Page  20                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    CONTROL                                | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
   Lung                                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
      Hemorrhage                           |             1                                                            |      1  1.0|
                                           |__________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
      Bilateral, Hydronephrosis            |       1                                                                  |      1  1.0|
                                           |__________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  M  +  +  +  +                                             |   9        |
 __________________________________________________________________________________________________________________________________ 
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  21                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    70 PPM                                 | 2| 2| 2| 2| 2| 2| 2| 2| 2| 3|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Liver                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Heart                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Testes                                  |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Spleen                                  |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Thymus                                  |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Brain                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
 _____________________________________________________________________________________________________________________|____________|
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                             Page  22                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    70 PPM                                 | 2| 2| 2| 2| 2| 2| 2| 2| 2| 3|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Lung                                    |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Kidney                                  |                                                                          |            |
 __________________________________________________________________________________________________________________________________ 
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  23                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    220 PPM                                | 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Liver                                   |          +     +                                                         |   2        |
      Basophilic Focus                     |                X                                                         |      1     |
                                           |__________________________________________________________________________|____________|
   Stomach, Forestomach                    |          +                                                               |   1        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Heart                                   |          +                                                               |   1        |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Testes                                  |          +                                                               |   1        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Spleen                                  |          +                                                               |   1        |
                                           |__________________________________________________________________________|____________|
   Thymus                                  |          +                                                               |   1        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
 _____________________________________________________________________________________________________________________|____________|
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                             Page  24                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    220 PPM                                | 4| 4| 4| 4| 4| 4| 4| 4| 4| 5|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 NERVOUS SYSTEM - cont                     |                                                                          |            |
   Brain                                   |          +                                                               |   1        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Lung                                    |          +                                                               |   1        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Kidney                                  |          +                                                               |   1        |
 __________________________________________________________________________________________________________________________________ 
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  25                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    700 PPM                                | 6| 6| 6| 6| 6| 6| 6| 6| 6| 7|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +     +  +  +  +                                             |   9        |
      Epithelium, Hyperplasia              | 2  4  3  4  3     4  4  2  1                                             |      9  3.0|
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
 _____________________________________________________________________________________________________________________|____________|
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                             Page  26                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    700 PPM                                | 6| 6| 6| 6| 6| 6| 6| 6| 6| 7|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 NERVOUS SYSTEM - cont                     |                                                                          |            |
   Brain                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 __________________________________________________________________________________________________________________________________ 
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  27                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    2200 PPM                               | 8| 8| 8| 8| 8| 8| 8| 8| 8| 9|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Liver                                   | +  +  +     +  +  +  +  +  +                                             |   9        |
      Vacuolization Cytoplasmic            |    2                 2  2                                                |      3  2.0|
                                           |__________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +     +  +  +  +  +                                                |   8        |
      Epithelium, Hyperplasia              | 2  4  2     2  3  4  2  2                                                |      8  2.6|
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Heart                                   | +  +  +     +  +  +  +  +  +                                             |   9        |
 _____________________________________________________________________________________________________________________|            |
 ENDOCRINE SYSTEM                          |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Testes                                  | +  +  +     +  +  +  +  +  +                                             |   9        |
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Spleen                                  | +  +  +     +  +  +  +  +  +                                             |   9        |
      Pigmentation, Melanin                |                      2                                                   |      1  2.0|
                                           |__________________________________________________________________________|____________|
   Thymus                                  | +  +  +     +  +  +  +  +  +                                             |   9        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                                                                                                    
                                                             Page  28                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      A     |
    2200 PPM                               | 8| 8| 8| 8| 8| 8| 8| 8| 8| 9|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Brain                                   | +  +  +     +  +  +  +  +  +                                             |   9        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Lung                                    | +  +  +     +  +  +  +  +  +                                             |   9        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Kidney                                  | +  +  +     +  +  +  +  +  +                                             |   9        |
 __________________________________________________________________________________________________________________________________ 
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  29                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                                            |      A     |
    7000 PPM                               | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 ALIMENTARY SYSTEM                         |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Esophagus                               | M  +  +  +  +  +  +  +  +  +                                             |   9        |
                                           |__________________________________________________________________________|____________|
   Gallbladder                             | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Large, Colon                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Large, Rectum                 | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Large, Cecum                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Small, Duodenum               | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Small, Jejunum                | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Intestine Small, Ileum                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Liver                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
      Vacuolization Cytoplasmic            | 2  2  2  1  2  2  2  2  1  2                                             |     10  1.8|
                                           |__________________________________________________________________________|____________|
   Pancreas                                | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Salivary Glands                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Stomach, Forestomach                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
      Epithelium, Hyperplasia              | 1  1  1  1  1  2  4  2  2                                                |      9  1.7|
                                           |__________________________________________________________________________|____________|
   Stomach, Glandular                      | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 CARDIOVASCULAR SYSTEM                     |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Blood Vessel                            | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Heart                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|____________|
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                             Page  30                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                                            |      A     |
    7000 PPM                               | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 ENDOCRINE SYSTEM                          |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Adrenal Cortex                          | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Adrenal Medulla                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Islets, Pancreatic                      | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Parathyroid Gland                       | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Pituitary Gland                         | +  +  +  +  +  +  M  +  +  +                                             |   9        |
                                           |__________________________________________________________________________|____________|
   Thyroid Gland                           | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 GENERAL BODY SYSTEM                       |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 GENITAL SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Epididymis                              | +  +  +  +  +  +  M  +  +  +                                             |   9        |
                                           |__________________________________________________________________________|____________|
   Preputial Gland                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Prostate                                | +  +  M  +  +  +  +  +  +  +                                             |   9        |
                                           |__________________________________________________________________________|____________|
   Seminal Vesicle                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Testes                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
      Atrophy                              |    1           1                                                         |      2  1.0|
 _____________________________________________________________________________________________________________________|            |
 HEMATOPOIETIC SYSTEM                      |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Bone Marrow                             | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Lymph Node, Bronchial                   | M  +  +  +  +  M  +  M  +  +                                             |   7        |
 _____________________________________________________________________________________________________________________|____________|
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                             Page  31                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                                            |      A     |
    7000 PPM                               | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 HEMATOPOIETIC SYSTEM - cont               |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Lymph Node, Mandibular                  | M  M  M  +  +  +  M  +  +  M                                             |   5        |
                                           |__________________________________________________________________________|____________|
   Lymph Node, Mesenteric                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Lymph Node, Mediastinal                 | M  M  M  M  M  +  M  +  +  M                                             |   3        |
                                           |__________________________________________________________________________|____________|
   Spleen                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
      Pigmentation                         |                      2                                                   |      1  2.0|
                                           |__________________________________________________________________________|____________|
   Thymus                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 INTEGUMENTARY SYSTEM                      |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Mammary Gland                           | M  M  M  M  M  M  M  M  M  M                                             |            |
                                           |__________________________________________________________________________|____________|
   Skin                                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 MUSCULOSKELETAL SYSTEM                    |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Bone                                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Skeletal Muscle                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 NERVOUS SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Brain                                   | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Peripheral Nerve                        | M  +  M  +  M  +  +  +  +  +                                             |   7        |
                                           |__________________________________________________________________________|____________|
   Spinal Cord                             | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 RESPIRATORY SYSTEM                        |                                                                          |            |
                                           |__________________________________________________________________________|____________|
 _____________________________________________________________________________________________________________________|____________|
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                             Page  32                                                               
                                                                                                                                   
NTP Experiment-Test: 05135-04                  NONNEOPLASTIC LESIONS BY INDIVIDUAL ANIMAL                         Report: PEIRPT09  
Study Type: SUBCHRON 90-DAY                                      ISOPRENE                                         Date: 10/15/04    
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 13:10:15    
 __________________________________________________________________________________________________________________________________ 
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |            |
                             DAY ON TEST   | 9| 9| 9| 9| 9| 9| 9| 9| 9| 9|                                            |            |
                                           | 3| 3| 3| 3| 3| 3| 3| 3| 3| 3|                                            |            |
 __________________________________________|__________________________________________________________________________|      T (*) |
                                           | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      O     |
   B6C3F1 MICE MALE                        | 0| 0| 0| 0| 0| 0| 0| 0| 0| 0|                                            |      T     |
                               ANIMAL ID   | 1| 1| 1| 1| 1| 1| 1| 1| 1| 1|                                            |      A     |
    7000 PPM                               | 0| 0| 0| 0| 0| 0| 0| 0| 0| 1|                                            |      L     |
                                           | 1| 2| 3| 4| 5| 6| 7| 8| 9| 0|                                            |            |
 _____________________________________________________________________________________________________________________|____________|
 RESPIRATORY SYSTEM - cont                 |                                                                          |            |
   Larynx                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Lung                                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Nose                                    | +  +  +  +  +  +  +  +  +  +                                             |  10        |
      Turbinate, Olfactory Epithelium,     |                                                                          |            |
           Degeneration                    | 2  2  2  1  2  2  2  1  2  1                                             |     10  1.7|
                                           |__________________________________________________________________________|____________|
   Trachea                                 | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 _____________________________________________________________________________________________________________________|            |
 SPECIAL SENSES SYSTEM                     |                                                                          |            |
    None                                   |                                                                          |            |
 _____________________________________________________________________________________________________________________|            |
 URINARY SYSTEM                            |                                                                          |            |
                                           |__________________________________________________________________________|____________|
   Kidney                                  | +  +  +  +  +  +  +  +  +  +                                             |  10        |
                                           |__________________________________________________________________________|____________|
   Urinary Bladder                         | +  +  +  +  +  +  +  +  +  +                                             |  10        |
 __________________________________________________________________________________________________________________________________ 
                                                                                                                                    
  * : Total animals with tissue examined microscopically; total animals with lesion and mean severity grade                         
  + : Tissue examined microscopically                M : Missing tissue                        1-4 : Lesion qualified as:           
  X : Lesion present but not qualified               A : Autolysis precludes examination               1) Minimal  3) Moderate      
  I : Insufficient tissue                        BLANK : Not examined                                  2) Mild     4) Marked        
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  33                                                               
                                                                                                                                   
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                             ----------              END OF REPORT             ----------                                           
                             ------------------------------------------------------------                                           
NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.